Passenger vehicles generally include a headliner which is positioned on the interior of the roof of the passenger compartment of the vehicle. Conventional headliners serve a variety of purposes. For example, the headliner serves as an aesthetic embellishment which obscures the inboard surface of the sheet metal of the roof of the vehicle as well as any vehicle components, such as wiring harness, conduits, ducts and the like, which may be affixed to the inboard surface of the roof. Conventional headliners are also used to mitigate the amount of environmental noise which enters the passenger compartment from sources external to the passenger compartment (i.e., road noise, engine noise, wind noise, etc.) to produce a more pleasurable driving experience for the vehicle occupants.
However, while conventional headliners are effective at mitigating environmental noise, such headliners also attenuate noise which originates from within the passenger compartment, such as speech and music. In cases where speech transmission is mitigated or attenuated, it may be difficult for passengers to carry on a conversation within the vehicle. Similarly, when a vehicle incorporates systems which are activated by voice commands, the mitigation or attenuation of speech transmission may make it difficult or impossible to properly operate these systems.
Accordingly, a need exists for headliners for vehicles with improved speech transmission characteristics and vehicles incorporating the same.